Since 2011, most original equipment manufacturers (OEMs) have been following ISO 26262 as a powerful standard for the functional safety of their vehicles’ e-powertrain. Thus, they invest huge amount of economic and human resource to ensure the compliance to this standard. However, the incorporation of functional safety into the e-powertrain of fuel cell vehicles is still a challenging task, as there are various of unexplored aspects for such systems. To address this problem, the standard needs to be thoroughly understood and systematically implemented. Nevertheless, the implementation is not a trivial task and requires a clear vision of the concept and the suggested methods of the standard. Therefore, this thesis clarifies both concept and product development phases (in the system level) of the standard, offering a practical example for the fuel cell system of a vehicle. A simplified model of the fuel cell system is utilized in order for the proposed method to be reproduceable. This approach provides, as work products, 1) the ‘item definition’ specifying the functionality of the system at the vehicle level, 2) the ‘hazard analysis and risk assessment’ identifying and categorizing the hazardous events resulting from malfunction of electric/electronic (E/E) devices, 3) ‘functional safety concept’ establishing functional safety requirements to achieve safety goals, and 4) ‘technical safety concept’ bringing the technical safety requirements for implementation by the system